Field of the Invention
The present invention generally relates to a pixel unit, a pixel array and a liquid crystal display panel, in particular, to a fringe field switching (FFS) pixel unit, a FFS pixel unit and a FFS liquid crystal display panel.
Description of Related Art
Nowadays, the functions that market demands of the liquid crystal display (LCD) panel are toward high contrast ratio, no gray scale inversion, little color shift, high luminance, high color richness, high color saturation, quick response, and wide viewing angle. The technologies that capable of fulfilling the requirements of wide viewing angle include, for example, a twisted nematic (TN) LCD panel having a wide viewing film, a in-plane switching (IPS) LCD panel, a fringe field switching (FFS) LCD panel and a multi-domain vertically alignment (MVA) LCD panel. Wherein, the fringe field switching LCD panel compared to twisted nematic LCD panel has better wide-viewing-angle effect.
In speaking of the fringe field switching LCD panel, in order to further improve finger press mura and disclination lines caused from the discontinuous alignment domains, a fringe field switching pixel unit of two-domain alignment has been provided, wherein there are designing patterns having large turning angles in the center of the pixel electrodes to provide two continuous alignment domains with different alignment effects. Nevertheless, in the junction between two alignment domains, the liquid crystal molecules in distribution area of curved patterns can not be driven smoothly; thereby the efficiency of liquid crystals decline. In this regard, another fringe field switching pixel unit of single-domain alignment (hereinafter referred to as 2D+ pixel unit) also has been provided, it fulfills the wide-viewing-angle effect through layout arrangements and tilting directions between a plurality of pixels. That is, a plurality of sub-pixels of pixel electrodes parallel to each other in the same row are designed to have a single tilting direction, and the sub-pixels of pixel electrodes in different rows are designed to have different tilting directions. In this manner, the designed curved patterns in the center of the pixel electrodes are eliminated, and thus the efficiency of liquid crystals is improved. However, due to the pixels in different rows having different alignment directions, therefore, in the case with polar viewing angles, the displaying images of the pixels in different rows will reveal different gamma curves, and the difference will be enlarged depending on the increment of the polar viewing angles, such that the Mura phenomenon of wide-viewing-angle displaying images in the row direction will become more obvious.